Can I drain/vent a sink into this drain pipe?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by pmayer, Sep 15, 2010.

  1. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    I am finishing a portion of my basement, and I am considering adding a wet bar if I can do it without breaking up concrete to run a drain. There is a good spot with a drain/vent adjacent, and easy access to water lines. But, my question is this. How can I tell if it is ok to tie a drain and vent into the this pipe?

    The PVC pipe is 2" as it comes up through the concrete floor, and then transitions to 1.5" after a foot or so. It is in the support wall going up through the middle of the house.

    Attached is a picture if that helps at all.

    Thanks for your help, as always...

    Paul

    Attached Files:

  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Why is that pipe there? Where does it go? Could it be a vent for a toilet rough-in that the builder installed under the floor in anticipation of a future remodel?

    It is too small to be a waste pipe from upper floors, but if it is a future toilet vent, it may not be installed in a way that you could use it as a drain/
  3. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    good question. We are the fourth owners of the house, and I don't know why it is there. It is very close to the drain in the basement floor. Could it be a vent for that? there is a toilet rough in, but it is perhaps 25 feet away from this spot, and appears to have a vent pipe in close proximity to it which is tied into all of the rough-in drains for the bathroom fixtures.
  4. Esquire

    Esquire Plumber

    Messages:
    65
    Location:
    Newfoundland
    That 3/4" Copper looks soft and appears to me that there is a ground wire on it. We I live the mains and sewers come in the same area. Could somebody have joined onto the main cleanout for the house and joined it up for what ever reason. maybe an attempt at a futurefixture of some sort. Where does it lead when it goes up the wall?
  5. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Yes, it is soft, and also has a ground wire. It is the main water supply and hooks into the meter just above the photo.

    The drain pipe goes to the basement ceiling, then turns 90 degrees and follows parallel with the ceiling for about 10 feet, and then heads straight up through the basement ceiling out of sight. It goes into the first floor in an area where there is no plumbing, and so I suspect that it continues straight up through the roof. It is possible that first floor fixtures use it as a vent, but not sure. This is a good distance from the main cleanout; probably 30 feet or so. It is possible that someone knew I was going to put a wet bar directly in that location 25 years later and plumbed for it. I would say that it was done as part of the original construction. The concrete has not been disturbed, and everything appears the same as the rest of the rough-in in the basement. My hunch is that it will be ok to tie into it, but is there a test of some sort that I can apply to be sure?
  6. Jerome2877

    Jerome2877 In the Trades

    Messages:
    397
    Location:
    BC
    I would open that clean out, then run water at each fixture to insure its not draining anything. Then I would want to check with a camera where it go's.
  7. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    sounds like a great plan! Thanks for the guidance...
  8. nukeman

    nukeman Nuclear Engineer

    Messages:
    711
    Location:
    VA
    I agree. Run water in the upstairs fixtures and see if you hear any water running down that pipe. Normally, things are tied together and come down in say a 3" pipe, but it is possible that it is for some fixture that isn't close to the other ones, so they broght it down on its own. The fact that there is a cleanout does suggest that it is a drain for something.

    Another possibility is that it has nothing to do with the DWV and it is there to remove radon from under the slab and vent it out the roof. This is why it is good to figure out what it is for before dumping anything down there. Not sure why there would be a cleanout if that was the case, but best to check.

    It goes to 2" probably because many places only allow 2" and larger under the slab.

    Anyway, looks like you'll have to look more and see if you can figure out what it is for.
  9. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Good suggestions Nukeman. There is active radon abatement through the sump basket, so I don't think this is related to that. But I will do some further investigation.
  10. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    If it's pretty close to a floor drain there is a good chance it's the floor drain vent in which case you can not technically use it because it would be a wet vent which is ok because a floor drain can be on a wet vent but a bar or kitchen sink can not.
  11. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Well, I found that I have a sink on the second floor that is draining into the pipe. So, I will use it as a drain, but I will have to figure out another place to vent. Thanks for the help guys!
  12. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    Please vent through the roof and not with an AAV.
  13. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    Ahhhh now you gone and put the idea in his head. Next time shhhhhhhhhhhh
  14. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Never heard of an AAV, but thanks, it looks like a nice simple solution to the problem. :)

    Since I never heard of those, I doubt we can do them here, but my inspector will be here in 3 hours to discuss options and I will see what he says about those. I don't think it will be difficult to tie into another vent. The drain was the trickier part.
  15. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,263
    Location:
    Cave Creek, Arizona
    That is a "cleanout tee", which implies that there is something above it using that pipe as a drain, therefore, you CANNOT use it for your new sink, unless you also provide a new venting method for it, and NOT an AAV mechanical vent.
  16. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Thank HJ. Yep, I have verified that there is a sink dumping into it from upstairs. So, I will be reviewing venting options with my inspector in 6 minutes....
  17. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    Not everyone picks hack solutions just because they've heard of them... :)
  18. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Yeah, if a quality solution is feasible, I would go for that every time. My inspector showed me a good way to vent the drain, and I forgot to ask about about the hack... :)
  19. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,263
    Location:
    Cave Creek, Arizona
    quote; My inspector showed me a good way to vent the drain,

    And HOW was that?
  20. pmayer

    pmayer New Member

    Messages:
    102
    Location:
    Minnesota
    Ah, yes, I guess I should have indicated that. He directed me to a vent on the other side of the basement. Not too gnarly a job, but not as easy as venting the sewer gas right into the family room with an AAV (Almost A Vent)... :)

    Thanks again for the help here, guys...
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